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Commit d7b6de14 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core/softlockup-for-linus' of... 

Merge branch 'core/softlockup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core/softlockup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softlockup: fix invalid proc_handler for softlockup_panic
  softlockup: fix watchdog task wakeup frequency
  softlockup: fix watchdog task wakeup frequency
  softlockup: show irqtrace
  softlockup: print a module list on being stuck
  softlockup: fix NMI hangs due to lock race - 2.6.26-rc regression
  softlockup: fix false positives on nohz if CPU is 100% idle for more than 60 seconds
  softlockup: fix softlockup_thresh fix
  softlockup: fix softlockup_thresh unaligned access and disable detection at runtime
  softlockup: allow panic on lockup
parents 30d38542 4dca10a9

Documentation/kernel-parameters.txt

+3 −0
Original line number Diff line number Diff line
@@ -2034,6 +2034,9 @@ and is between 256 and 4096 characters. It is defined in the file 


	snd-ymfpci=	[HW,ALSA]



	softlockup_panic=

			[KNL] Should the soft-lockup detector generate panics.



	sonypi.*=	[HW] Sony Programmable I/O Control Device driver

			See Documentation/sonypi.txt

include/linux/sched.h

+2 −1
Original line number Diff line number Diff line
@@ -295,10 +295,11 @@ extern void softlockup_tick(void); 
extern void spawn_softlockup_task(void);

extern void touch_softlockup_watchdog(void);

extern void touch_all_softlockup_watchdogs(void);

extern unsigned long  softlockup_thresh;

extern unsigned int  softlockup_panic;

extern unsigned long sysctl_hung_task_check_count;

extern unsigned long sysctl_hung_task_timeout_secs;

extern unsigned long sysctl_hung_task_warnings;

extern int softlockup_thresh;

#else

static inline void softlockup_tick(void)

{

kernel/softlockup.c

+38 −7
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/delay.h>

#include <linux/freezer.h>

#include <linux/kthread.h>

#include <linux/lockdep.h>

#include <linux/notifier.h>

#include <linux/module.h>
@@ -25,7 +26,22 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp); 
static DEFINE_PER_CPU(struct task_struct *, watchdog_task);



static int __read_mostly did_panic;

unsigned long __read_mostly softlockup_thresh = 60;

int __read_mostly softlockup_thresh = 60;



/*

 * Should we panic (and reboot, if panic_timeout= is set) when a

 * soft-lockup occurs:

 */

unsigned int __read_mostly softlockup_panic =

				CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;



static int __init softlockup_panic_setup(char *str)

{

	softlockup_panic = simple_strtoul(str, NULL, 0);



	return 1;

}

__setup("softlockup_panic=", softlockup_panic_setup);



static int

softlock_panic(struct notifier_block *this, unsigned long event, void *ptr)
@@ -84,6 +100,14 @@ void softlockup_tick(void) 
	struct pt_regs *regs = get_irq_regs();

	unsigned long now;



	/* Is detection switched off? */

	if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) {

		/* Be sure we don't false trigger if switched back on */

		if (touch_timestamp)

			per_cpu(touch_timestamp, this_cpu) = 0;

		return;

	}



	if (touch_timestamp == 0) {

		__touch_softlockup_watchdog();

		return;
@@ -92,11 +116,8 @@ void softlockup_tick(void) 
	print_timestamp = per_cpu(print_timestamp, this_cpu);



	/* report at most once a second */

	if ((print_timestamp >= touch_timestamp &&

			print_timestamp < (touch_timestamp + 1)) ||

			did_panic || !per_cpu(watchdog_task, this_cpu)) {

	if (print_timestamp == touch_timestamp || did_panic)

		return;

	}



	/* do not print during early bootup: */

	if (unlikely(system_state != SYSTEM_RUNNING)) {
@@ -106,8 +127,11 @@ void softlockup_tick(void) 


	now = get_timestamp(this_cpu);



	/* Wake up the high-prio watchdog task every second: */

	if (now > (touch_timestamp + 1))

	/*

	 * Wake up the high-prio watchdog task twice per

	 * threshold timespan.

	 */

	if (now > touch_timestamp + softlockup_thresh/2)

		wake_up_process(per_cpu(watchdog_task, this_cpu));



	/* Warn about unreasonable delays: */
@@ -121,11 +145,15 @@ void softlockup_tick(void) 
			this_cpu, now - touch_timestamp,

			current->comm, task_pid_nr(current));

	print_modules();

	print_irqtrace_events(current);

	if (regs)

		show_regs(regs);

	else

		dump_stack();

	spin_unlock(&print_lock);



	if (softlockup_panic)

		panic("softlockup: hung tasks");

}



/*
@@ -178,6 +206,9 @@ static void check_hung_task(struct task_struct *t, unsigned long now) 


	t->last_switch_timestamp = now;

	touch_nmi_watchdog();



	if (softlockup_panic)

		panic("softlockup: blocked tasks");

}



/*

kernel/sysctl.c

+16 −4
Original line number Diff line number Diff line
@@ -88,12 +88,13 @@ extern int rcutorture_runnable; 
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */



/* Constants used for minimum and  maximum */

#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM)

#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)

static int one = 1;

#endif



#ifdef CONFIG_DETECT_SOFTLOCKUP

static int sixty = 60;

static int neg_one = -1;

#endif



#ifdef CONFIG_MMU
@@ -737,15 +738,26 @@ static struct ctl_table kern_table[] = { 
	},

#endif

#ifdef CONFIG_DETECT_SOFTLOCKUP

	{

		.ctl_name	= CTL_UNNUMBERED,

		.procname	= "softlockup_panic",

		.data		= &softlockup_panic,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= &proc_dointvec_minmax,

		.strategy	= &sysctl_intvec,

		.extra1		= &zero,

		.extra2		= &one,

	},

	{

		.ctl_name	= CTL_UNNUMBERED,

		.procname	= "softlockup_thresh",

		.data		= &softlockup_thresh,

		.maxlen		= sizeof(unsigned long),

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= &proc_doulongvec_minmax,

		.proc_handler	= &proc_dointvec_minmax,

		.strategy	= &sysctl_intvec,

		.extra1		= &one,

		.extra1		= &neg_one,

		.extra2		= &sixty,

	},

	{

kernel/time/tick-sched.c

+2 −2
Original line number Diff line number Diff line
@@ -140,8 +140,6 @@ void tick_nohz_update_jiffies(void) 
	if (!ts->tick_stopped)

		return;



	touch_softlockup_watchdog();



	cpu_clear(cpu, nohz_cpu_mask);

	now = ktime_get();

	ts->idle_waketime = now;
@@ -149,6 +147,8 @@ void tick_nohz_update_jiffies(void) 
	local_irq_save(flags);

	tick_do_update_jiffies64(now);

	local_irq_restore(flags);



	touch_softlockup_watchdog();

}



void tick_nohz_stop_idle(int cpu)